"Sex Differences" serves as an advanced text for courses in evolutionary and human biology, psychology, and sexuality and gender studies. It also serves as a reference source for academic professionals in these disciplines. The book covers the evolution of sex and sex differences, and sex differences and sexual strategies in non-human and human animals. The final chapter addresses issues of sex and gender in interpersonal relationships, organizations and politics. Diagrams, graphs, charts, and tables illustrate key concepts; cartoons and photos provide visual breaks and an element of humor. It examines sexual differences from a multi-level comparative approach and contains a thorough coverage of literature through 1998 and into 1999. It illustrates pages with a generous use of cartoons, photos, figures, and diagrams. It invites bonus learning with special interest boxes interspersed throughout text and presents a critical analysis. It includes a combination of feminist and evolutionary thinking.